Beconase

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CLINICAL PHARMACOLOGY

Beclomethasone 17,21-dipropionate is a diester of beclomethasone, a synthetic halogenated corticosteroid. Animal studies show that beclomethasone dipropionate has potent glucocorticoid and weak mineralocorticoid activity.

The mechanisms responsible for the anti-inflammatory action of beclomethasone dipropionate are unknown. The precise mechanism of the aerosolized drug's action in the nose is also unknown. Biopsies of nasalmucosa obtained during clinical studies showed no histopathologic changes when beclomethasone dipropionate was administered intranasally.The effect of beclomethasone dipropionate on hypothalamic-pituitary-adrenal (HPA) function have been evaluated in adult volunteers by other routes of administration. Studies with beclomethasone dipropionate by the intranasal route which may demonstrate that there is more or that there is less absorption by this route of administration. There was no suppression of early morning plasmacortisol concentrations when beclomethasone dipropionate was administered in a dose of 1000 mcg per day for 1 month as an oral aerosol or for 3 days by IM injection. However, partial suppression of plasma cortisol concentration was observed when beclomethasone dipropionate was administered in doses of 2000 mcg per day either by oral aerosol or intramuscular injection form. Immediate suppression of plasma cortisol concentrations was observed after single doses of 4000 mcg of beclomethasone dipropionate. Suppression of HPA function (reduced early morning plasma cortisol levels) has been reported in adult patients who received 1600-mcg daily doses of oral beclomethasone dipropionate for 1 month. In clinical studies using beclomethasone dipropionate intranasally, there was no evidence of adrenal insufficiency.

The effect of beclomethasone dipropionate nasal spray on HPA function was not evaluated but would not be expected to differ from intranasal beclomethasone dipropionate aerosol.

In one study in asthmatic children, the administration of inhaled beclomethasone at recommended daily doses for at least 1 year was associated with a reduction in nocturnal cortisol secretion. The clinical significance of this finding is not clear. It reinforces other evidence, however, that topical beclomethasone may be absorbed in amounts that can have systemic effects and that physicians should be alert for evidence of systemic effects, especially in chronically treated patients (see PRECAUTIONS).

Beclomethasone dipropionate is sparingly soluble. When given by nasal inhalation in the form of an aqueous or aerosolized suspension, the drug is deposited primarily in the nasal passages. A portion of the drug is swallowed. Absorption occurs rapidly from all respiratory and gastrointestinal tissues. There is no evidence of tissue storage of beclomethasone dipropionate or its metabolites. In vitro studies have shown that tissue other than the liver (lung slices) can rapidly metabolize beclomethasone dipropionate to beclomethasone 17- monopropionate and more slowly to free becloethasone (which has very weak anti-inflammatory activity). However, irrespective of the route of entry, the principal route of excretion of the drug and its metabolites is the feces. In humans, 12% to 15% of an orally administered dose of beclomethasone dipropionate is excreted in the urine as both conjugated and free metabolites of the drug.

Studies have shown that the degree of binding to plasma proteins is 87%.

Last reviewed on RxList: 12/8/2004
This monograph has been modified to include the generic and brand name in many instances.